Conventional wireless subscriber stations employ radio-frequency (RF) transmitters to produce an output signal that is transmitted to the base station (BS). In mobile wireless networks, one station may be a mobile station (MS), whereas another station may be a BS (BS). As the MS moves throughout the coverage area of the wireless network, the path loss between the MS and the BS changes due to a number of factors including the change in distance between the stations as well as the presence of objects in the environment that serve to obstruct or attenuate the signals traveling from one station to the other.
A critical component in a MS is the power amplifier that is used to transmit the signal to the BS. A power amplifier typically has a maximum output power rating. One method to attain reliable communication with a BS is to ensure that the power amplifier is equipped with sufficient power to overcome the fading and path loss present in a wireless medium.
However, it is not generally feasible to equip an MS with an arbitrarily high-power amplifier for several reasons: (i) there is a limit on the total power that may be consumed by the device; (ii) a high-power amplifier may get excessively warm; (iii) a high-power amplifier may be expensive; (iv) a high-power amplifier may be too large to fit within the size constraints of a small mobile terminal; (v) a high power amplifier may exceed specific absorption rate limits designed to protect safety.
Further limitations and disadvantages of conventional and traditional approaches will become apparent to one of skill in the art, through comparison of such systems with some aspects of the present invention as set forth in the remainder of the present application with reference to the drawings.